/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.dolphinscheduler.common.utils;

import org.apache.dolphinscheduler.common.constants.Constants;

import org.apache.http.HttpEntity;
import org.apache.http.client.config.AuthSchemes;
import org.apache.http.client.config.CookieSpecs;
import org.apache.http.client.config.RequestConfig;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.config.Registry;
import org.apache.http.config.RegistryBuilder;
import org.apache.http.conn.socket.ConnectionSocketFactory;
import org.apache.http.conn.socket.PlainConnectionSocketFactory;
import org.apache.http.conn.ssl.NoopHostnameVerifier;
import org.apache.http.conn.ssl.SSLConnectionSocketFactory;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClientBuilder;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.impl.conn.PoolingHttpClientConnectionManager;
import org.apache.http.util.EntityUtils;

import java.io.IOException;
import java.security.KeyManagementException;
import java.security.NoSuchAlgorithmException;
import java.security.cert.X509Certificate;
import java.util.Arrays;
import java.util.Objects;

import javax.net.ssl.SSLContext;
import javax.net.ssl.TrustManager;
import javax.net.ssl.X509TrustManager;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * http utils
 */
public class HttpUtils {

  public static final Logger logger = LoggerFactory.getLogger(HttpUtils.class);

  private HttpUtils() {
    throw new UnsupportedOperationException("Construct HttpUtils");
  }

  public static CloseableHttpClient getInstance() {
    return HttpClientInstance.httpClient;
  }

  private static class HttpClientInstance {
    private static final CloseableHttpClient httpClient = getHttpClientBuilder().build();
  }

  public static HttpClientBuilder getHttpClientBuilder() {
    return HttpClients.custom().setConnectionManager(cm).setDefaultRequestConfig(requestConfig);
  }

  private static PoolingHttpClientConnectionManager cm;

  private static SSLContext ctx = null;

  private static SSLConnectionSocketFactory socketFactory;

  private static RequestConfig requestConfig;

  private static Registry<ConnectionSocketFactory> socketFactoryRegistry;

  private static X509TrustManager xtm = new X509TrustManager() {
    @Override
    public void checkClientTrusted(X509Certificate[] chain, String authType) {
    }

    @Override
    public void checkServerTrusted(X509Certificate[] chain, String authType) {
    }

    @Override
    public X509Certificate[] getAcceptedIssuers() {
      return null;
    }
  };

  static {
    try {
      ctx = SSLContext.getInstance(SSLConnectionSocketFactory.TLS);
      ctx.init(null, new TrustManager[]{xtm}, null);
    } catch (NoSuchAlgorithmException e) {
      logger.error("SSLContext init with NoSuchAlgorithmException", e);
    } catch (KeyManagementException e) {
      logger.error("SSLContext init with KeyManagementException", e);
    }
    socketFactory = new SSLConnectionSocketFactory(ctx, NoopHostnameVerifier.INSTANCE);
    /** set timeout、request time、socket timeout */
    requestConfig = RequestConfig.custom().setCookieSpec(CookieSpecs.IGNORE_COOKIES)
        .setExpectContinueEnabled(Boolean.TRUE)
        .setTargetPreferredAuthSchemes(Arrays.asList(AuthSchemes.NTLM, AuthSchemes.DIGEST, AuthSchemes.SPNEGO))
        .setProxyPreferredAuthSchemes(Arrays.asList(AuthSchemes.BASIC, AuthSchemes.SPNEGO))
        .setConnectTimeout(Constants.HTTP_CONNECT_TIMEOUT).setSocketTimeout(Constants.SOCKET_TIMEOUT)
        .setConnectionRequestTimeout(Constants.HTTP_CONNECTION_REQUEST_TIMEOUT).setRedirectsEnabled(true)
        .build();
    socketFactoryRegistry = RegistryBuilder.<ConnectionSocketFactory>create()
        .register("http", PlainConnectionSocketFactory.INSTANCE).register("https", socketFactory).build();
    cm = new PoolingHttpClientConnectionManager(socketFactoryRegistry);
    cm.setDefaultMaxPerRoute(60);
    cm.setMaxTotal(100);

  }

  /**
   * get http request content
   *
   * @param url url
   * @return http get request response content
   */
  public static String get(String url) {
    CloseableHttpClient httpclient = HttpUtils.getInstance();

    HttpGet httpget = new HttpGet(url);
    return getResponseContentString(httpget, httpclient);
  }

  /**
   * get http response content
   *
   * @param httpget    httpget
   * @param httpClient httpClient
   * @return http get request response content
   */
  public static String getResponseContentString(HttpGet httpget, CloseableHttpClient httpClient) {
    if (Objects.isNull(httpget) || Objects.isNull(httpClient)) {
      logger.error("HttpGet or HttpClient parameter is null");
      return null;
    }
    String responseContent = null;
    CloseableHttpResponse response = null;
    try {
      response = httpClient.execute(httpget);
      // check response status is 200
      if (response.getStatusLine().getStatusCode() == 200) {
        HttpEntity entity = response.getEntity();
        if (entity != null) {
          responseContent = EntityUtils.toString(entity, Constants.UTF_8);
        } else {
          logger.warn("http entity is null");
        }
      } else {
        logger.error("http get:{} response status code is not 200!", response.getStatusLine().getStatusCode());
      }
    } catch (IOException ioe) {
      logger.error(ioe.getMessage(), ioe);
    } finally {
      try {
        if (response != null) {
          EntityUtils.consume(response.getEntity());
          response.close();
        }
      } catch (IOException e) {
        logger.error(e.getMessage(), e);
      }
      if (!httpget.isAborted()) {
        httpget.releaseConnection();
        httpget.abort();
      }

    }
    return responseContent;
  }

}
